短視頻程序源碼Android Studio實現簡單音樂播放功能

主要代碼
1 主頁面

package com.example.dell.musicbox3;

import  android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.media.AudioManager;
import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.widget.ImageButton;
import android.widget.SeekBar;
import android.widget.TextView;


public class MainActivity extends Activity implements View.OnClickListener
{
	// 獲取界面中顯示歌曲標題、作者文本框
	TextView title, author;
	// 播放/暫停、停止按鈕
	ImageButton play, next, last;
	// 聲明音量管理器
	public AudioManager mAudioManager = null;
	// 定義進度條
	public static SeekBar audioSeekBar = null;
	// 定義音量大小
	public SeekBar audioVolume = null;

	ActivityReceiver activityReceiver;

	public static final String CTL_ACTION = "org.crazyit.action.CTL_ACTION";

	public static final String UPDATE_ACTION = "org.crazyit.action.UPDATE_ACTION";
	// 定義音樂的播放狀態，0x11代表沒有播放；0x12代表正在播放；0x13代表暫停
	int status = 0x11;
	String[] titleStrs = new String[] { "龍捲風", "可愛女人", "星晴" };
	String[] authorStrs = new String[] { "JayChou", "JayChou", "JayChou" };

	@Override
	public void onCreate(Bundle savedInstanceState)
	{
		super.onCreate(savedInstanceState);
		requestWindowFeature(Window.FEATURE_NO_TITLE);
		setContentView(R.layout.layout);

		// 獲取程序界面界面中的兩個按鈕
		play = (ImageButton) this.findViewById(R.id.play);
		last = (ImageButton) this.findViewById(R.id.last);
		next = (ImageButton) this.findViewById(R.id.next);
		audioVolume = (SeekBar) findViewById(R.id.seekBar2);
		audioSeekBar = (SeekBar) findViewById(R.id.seekBar1);
		title = (TextView) findViewById(R.id.title);
		author = (TextView) findViewById(R.id.author);


		// 爲兩個按鈕的單擊事件添加監聽器
		play.setOnClickListener(this);
		last.setOnClickListener(this);
		next.setOnClickListener(this);

		// 播放進度監聽
		audioSeekBar.setOnSeekBarChangeListener(new SeekBarChangeEvent());
		// 退出後再次進去程序時，進度條保持持續更新
		if (MusicService.mPlayer != null) {
			// 設置進度條的最大值
			MainActivity.audioSeekBar.setMax(MusicService.mPlayer.getDuration());
			audioSeekBar.setProgress(MusicService.mPlayer.getCurrentPosition());
		}
		// 得到當前音量對象
		mAudioManager = (AudioManager) getSystemService(AUDIO_SERVICE);
		// 把當前音量值賦給進度條
		audioVolume.setProgress(mAudioManager
				.getStreamVolume(AudioManager.STREAM_MUSIC));
		// 監聽音量
		audioVolume.setOnSeekBarChangeListener(new AudioVolumeChangeEvent());


		activityReceiver = new ActivityReceiver();
		// 創建IntentFilter
		IntentFilter filter = new IntentFilter();
		// 指定BroadcastReceiver監聽的Action
		filter.addAction(UPDATE_ACTION);
		// 註冊BroadcastReceiver
		registerReceiver(activityReceiver, filter);

		Intent intent = new Intent(this, MusicService.class);
		// 啓動後臺Service
		startService(intent);
	}

	// 音量監聽
	class AudioVolumeChangeEvent implements SeekBar.OnSeekBarChangeListener {

		@Override
		public void onProgressChanged(SeekBar seekBar, int progress,
									  boolean fromUser) {
			mAudioManager.setStreamVolume(AudioManager.STREAM_MUSIC, progress,
					0);
		}

		@Override
		public void onStartTrackingTouch(SeekBar seekBar) {

		}

		@Override
		public void onStopTrackingTouch(SeekBar seekBar) {

		}

	}

	// 播放進度監聽，別忘了Service裏面還有個進度條刷新
	class SeekBarChangeEvent implements SeekBar.OnSeekBarChangeListener {

		@Override
		public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
			// 假設改變源於用戶拖動
			if (fromUser) {
				MusicService.mPlayer.seekTo(progress);
				// 當進度條的值改變時，音樂播放器從新的位置開始播放
			}
		}

		@Override
		public void onStartTrackingTouch(SeekBar seekBar) {
			MusicService.mPlayer.pause();
		}

		@Override
		public void onStopTrackingTouch(SeekBar seekBar) {
			MusicService.mPlayer.start();
		}

	}


	// 自定義的BroadcastReceiver，負責監聽從Service傳回來的廣播
	public class ActivityReceiver extends BroadcastReceiver
{
	@Override
	public void onReceive(Context context, Intent intent)
	{
		// 獲取Intent中的update消息，update代表播放狀態
		int update = intent.getIntExtra("update", -1);
		// 獲取Intent中的current消息，current代表當前正在播放的歌曲
		int current = intent.getIntExtra("current", -1);
		if (current >= 0)
		{
			title.setText(titleStrs[current]);
			author.setText(authorStrs[current]);
		}
		switch (update)
		{
			case 0x11:
				play.setImageResource(R.drawable.play);
				status = 0x11;
				break;
			// 控制系統進入播放狀態
			case 0x12:
				// 播放狀態下設置使用暫停圖標
				play.setImageResource(R.drawable.pause);
				// 設置當前狀態
				status = 0x12;
				break;
			// 控制系統進入暫停狀態
			case 0x13:
				// 暫停狀態下設置使用播放圖標
				play.setImageResource(R.drawable.play);
				// 設置當前狀態
				status = 0x13;
				break;
		}
	}
}
	@Override
	public void onClick(View source)
	{
		// 創建Intent
		Intent intent = new Intent("org.crazyit.action.CTL_ACTION");
		switch (source.getId())
		{
			// 按下播放/暫停按鈕
			case R.id.play:
				intent.putExtra("control", 1);
				break;
			case R.id.last:
				intent.putExtra("control", 2);
				break;
			//按下上一首按鈕
			case R.id.next:
				intent.putExtra("control", 3);
				break;
		}
		// 發送廣播，將被Service組件中的BroadcastReceiver接收到
		sendBroadcast(intent);
	}

}

2 音樂服務端

package com.example.dell.musicbox3;

import java.io.IOException;

import android.app.Service;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.res.AssetFileDescriptor;
import android.content.res.AssetManager;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnCompletionListener;
import android.os.IBinder;

public class MusicService extends Service implements Runnable
{
	MyReceiver serviceReceiver;
	//asset文件管理對象
	AssetManager am;
	String[] musics = new String[] { "周杰倫 - 龍捲風.mp3", "周杰倫 - 星晴.mp3", "周杰倫 - 可愛女人.mp3" };
	public static MediaPlayer mPlayer;
	// 當前的狀態，0x11代表沒有播放；0x12代表正在播放；0x13代表暫停
	int status = 0x11;
	// 記錄當前正在播放的音樂
	int current = 0;
	@Override
	//非綁定式服務
	public IBinder onBind(Intent intent)
	{
		return null;
	}
	@Override
	//定義初始化函數
	public void onCreate()
	{
		super.onCreate();
		//獲取asset文件夾裏的所有歌曲
		am = getAssets();
		// 創建具有篩選功能的服務端接收器
		serviceReceiver = new MyReceiver();
		// 創建IntentFilter過濾器
		IntentFilter filter = new IntentFilter();
		//使音樂服務端的接收器只能接收客戶端發來的CTL_ACTION消息
		filter.addAction(MainActivity.CTL_ACTION);
		//註冊帶有此篩選器且名字叫做serviceReceiver的接收器
		registerReceiver(serviceReceiver, filter);
		// 創建MediaPlayer
		mPlayer = new MediaPlayer();
		// 爲MediaPlayer播放完成事件綁定監聽器
		mPlayer.setOnCompletionListener(new OnCompletionListener() // ①
		{
			@Override
			public void onCompletion(MediaPlayer mp)
			{
				current++;
				if (current >= 3)
				{
					current = 0;
				}
				//發送廣播通知Activity更改文本框
				Intent sendIntent = new Intent(MainActivity.UPDATE_ACTION);
				sendIntent.putExtra("current", current);
				// 發送廣播，將被Activity組件中的BroadcastReceiver接收到
				sendBroadcast(sendIntent);
				// 準備並播放音樂
				prepareAndPlay(musics[current]);
			}
		});
	}
	public class MyReceiver extends BroadcastReceiver
{
	@Override
	public void onReceive(final Context context, Intent intent)
	{
		int control = intent.getIntExtra("control", -1);
		switch (control)
		{
			// 播放或暫停
			case 1:
				// 原來處於沒有播放狀態
				if (status == 0x11)
				{
					// 準備並播放音樂
					prepareAndPlay(musics[current]);
					status = 0x12;
				}
				// 原來處於播放狀態
				else if (status == 0x12)
				{
					// 暫停
					mPlayer.pause();
					// 改變爲暫停狀態
					status = 0x13;
				}
				// 原來處於暫停狀態
				else if (status == 0x13)
				{
					// 播放
					mPlayer.start();
					// 改變狀態
					status = 0x12;
				}
				break;
			// 停止聲音
			case 2:
				//上一首切換
				if (current <= 0) {
					//停止播放
					mPlayer.stop();
					//修改current
					current = musics.length-1;
					//播放
					prepareAndPlay(musics[current]);
					status = 0x12;
				}
				else{
					mPlayer.stop();
					current--;
					prepareAndPlay(musics[current]);
					status = 0x12;
				}
				break;
			//下一首切換
			case 3:
				if (current >= 2) {
					mPlayer.stop();
					current = 0;
					prepareAndPlay(musics[current]);
					status = 0x12;
				}
				else{
					mPlayer.stop();
					current++;
					prepareAndPlay(musics[current]);
					status = 0x12;
				}
				break;

		}
		// 廣播通知Activity更改圖標、文本框
		Intent sendIntent = new Intent(MainActivity.UPDATE_ACTION);
		sendIntent.putExtra("update", status);
		sendIntent.putExtra("current", current);
		// 發送廣播，將被Activity組件中的BroadcastReceiver接收到
		sendBroadcast(sendIntent);
	}
}
	private void prepareAndPlay(String music) {
		try {
			// 打開指定音樂文件
			AssetFileDescriptor afd = am.openFd(music);
			mPlayer.reset();
			// 使用MediaPlayer加載指定的聲音文件。
			mPlayer.setDataSource(afd.getFileDescriptor(),
					afd.getStartOffset(), afd.getLength());
			// 準備聲音
			mPlayer.prepare();
			// 播放
			mPlayer.start();
			// 設置進度條最大值
			MainActivity.audioSeekBar.setMax(MusicService.mPlayer.getDuration());
			new Thread(this).start();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	// 刷新進度條
	public void run() {
		int CurrentPosition = 0;
		int total = mPlayer.getDuration();
		while (mPlayer != null && CurrentPosition < total) {
			try {
				Thread.sleep(1000);
				if (mPlayer != null) {
					CurrentPosition = mPlayer.getCurrentPosition();
				}
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
			MainActivity.audioSeekBar.setProgress(CurrentPosition);
		}
	}
}